Question

5) B-Ch 19 (2 pts) The electric field at point Pdue to a point charge a distance Raway from Phas magnitude E. In order to double the magnitude of the field at P you could reduce the distance to R2. )double the charge to 20 and at the same time reduce the distance to R2. C) double the charge to 20 D double the distance to 2/R E) reduce the distance to RY4 6) Ch 18 (4 pts) A gas is taken through the cycle shown in the pVdiagram in the figure. During one cycle, how much work is done by the gas? CLOsca 2po Po 2% 3% 4% D)3/0角 B) 2 poo Cypo'o

Answer 1

5 )

E = kQ/R^2

if distance = R/2

E' = 4Qk/R^2 = 4E  

if we double the charge and half the distance

E' = 8E  

double the charge Q

E' = 2E ( C option )

part 6 )

W = pdv

at constant volume W = 0

W = 0 + 2po(4vo-vo) + 0 + po(vo-4vo)

W = 6povo - 3povo = 3povo ( D option )